RESEARCH

2002

Augmented Paleontology

Zoom: Click on Image Paleontology is filled with mysteries about the plants and animals that lived thousands, millions, even billions of years before the first humans walked the earth. To answer questions about these organisms, paleontologists rely on the excavation, analysis, and interpretation of fossils. Embedded and preserved in the earth’s crust, fossils are the remains or traces of ancient life forms, including bones, teeth, shells, leaf imprints, nests, and footprints.Fossils can disclose how organisms evolved over time and their relationship to one another. While they reveal much, such as the general shape and size of ancient living things, fossils keep us guessing about these organisms’ color, sound, and—most significantly—their behavior. For several years, modern paleontologists have used 3D computer graphics to help reconstruct these pieces of the past. State-of-the-art scanning technology produces 3D fossil replicas that scientists can process and study without physical constraints. Paleontologists typically generate volumetric data sets for analysis, such as magnetic resonance imaging or computed axial tomography scans, and they use surface models for digital preservation and reproduction. To study ontogeny—an organism’s growth and form—paleontologists apply mathematical models for simulation and visualization. Likewise, computer animations help study dinosaur locomotion. Beyond building knowledge of our world, the results of this work influence how dinosaurs appear in museums, illustrations, and movies, and as toys. In the past 40 years, technological advances have continued to blur the boundary between real and computer-generated worlds. Augmented reality leverages this technology to provide an interface that enhances the real world with synthetic supplements. Paleontologists can use AR to present virtual data, such as 3D computer graphics, directly within a real environment rather than on a flat monitor. We coined the term augmented paleontology to refer to the application of AR to paleontology. AP seeks to support paleontologists in their research, and communicate the results of paleontology to museum visitors in an exciting and effective way. An interdisciplinary team of paleontologists, graphics designers, and computer scientists has already applied the AP interface to soft-tissue reconstruction and the study of dinosaur locomotion.

Bimber, O., Gatesy, S.M., Witmer, L.M., Raskar, R. and Encarnação, L.M. Merging Fossil Specimens with Computer-Generated Information IEEE Computer, September, pp. 45-50, 2002 Movie 1 (~74MB) Movie 2 (~95MB)

Occlusion Shadows

Zoom: Click on Image Projection-based augmented reality systems, such as the Virtual Showcase, share many positive properties of projection-based virtual environments. These displays provide high resolution, improved consistency of eye accommodation and convergence, little motion sickness potential, and the possibility of an integration into common working environments. One of the main challenges for projection-based AR systems as well as for head-mounted optical see-through displays is the generation of correct occlusion effects between virtual and real objects. Additionally shadows of virtual objects cast onto real ones and consistent illumination of the real and virtual scenery are often difficult to achieve. We introduce projector-based illumination techniques for view-dependent optical seethrough AR displays. This approach has the potential to solve all of the above mentioned problems. Here, we focus on using projector-based illumination for creating correct occlusion effects for mixed reality configurations. We have implemented and tested such a system in the context of the Virtual Showcase, which consists of a horizontal projection screen and a convex half-silvered mirror assembly. Virtual and real objects can be displayed in the same space inside the showcase. The original Virtual Showcase used a standard light bulb to illuminate real objects. This setup does not provide very much control over the lighting situation. By using a computer-controlled video-projector as a replacement for the simple light bulb, we are able to fully control the lighting situation inside the showcase on a perpixel basis. Our main contribution is a solution to the problem of correct occlusion for mixed reality scenarios with viewdependent optical see-through displays. Our method produces correct occlusion effects between virtual and real objects by projecting shadows onto real objects located behind virtual ones using projector-based illumination.

Bimber, O. and Fröhlich, B. Occlusion Shadows: Using Projected Light to Generate Realistic Occlusion Effects for View-Dependent Optical See-Through Displays In proceedings of International Symposium on Mixed and Augmented Reality (ISMAR’02), pp. 186-195, 2002 Movie (~91MB)